Display screen or portion thereof with transitional graphical user interface



FIG. 1 is the first image in a sequence of a display screen or portionthereof with transitional graphical user interface showing our newdesign;

FIG. 2 is the second image in a sequence thereof;

FIG. 3 is the third image in a sequence thereof;

FIG. 4 is the fourth image in a sequence thereof;

FIG. 5 is a fifth image in a sequence thereof;

FIG. 6 is a sixth image in a sequence thereof;

FIG. 7 is a seventh image in a sequence thereof; and,

FIG. 8 is an eighth image in a sequence thereof.

The broken lines in the figures depict portions of the graphical userinterface that form no part of the claimed design.

The outermost broken line showing of the display screen or portionthereof is for environmental purposes only and forms no part of theclaimed design.

The appearance of the transitional graphical user interface sequentiallytransitions between the images shown in FIGS. 1 through 8. The processor period in which one image transitions to another forms no part of theclaimed design.

CLAIM We claim the ornamental design for a display screen or portionthereof with transitional graphical user interface, as shown anddescribed.